The design of sheet metal parts usually requires the folding, stamping, or cutting of sheets of metal to provide desired shapes. Designers usually develop parts using a folded three-dimensional (3D) model. Once the 3D design has been completed, however, it is a two-dimensional (2D) counterpart that is transferred to the manufacturing line to manufacture the part. The 2D unfolded model of the part can be produced during or at the end of the design process. Because certain design operations can only be conducted on the unfolded version, the folded and unfolded versions are typically designed concurrently. For example, where a hole feature needs to be inserted at a precisely defined location on some element of the part, the 3D folded model does not always provide the degree of accuracy required and the user often needs access to an unfolded design version.
In currently available sheet metal part design systems, specific fold and unfold features are made available to users. When a user working on the folded version of the part inserts an unfold feature in the design, the system computes the required geometric transformations to go from the folded design to the corresponding unfolded design. The display controller of the system then displays the updated unfolded version to the user. When the user has completed the design task on the unfolded version, she may insert a fold feature in the design to cause the system to compute the reverse transformations so as to produce the folded version of the modified part. The display controller of the system then updates and displays the folded version to the user. In the design of complex parts, it is not unusual to find a large number of such fold and unfold features scattered throughout the design process tree.
The known technique of inserting fold-unfold features as needed has a number of drawbacks. The insertion of fold-unfold features does not play any actual role in the part design process and increases the complexity of the process. It also introduces severe constraints on the user when sequencing the various design operations. Reordering the features, for example, can be performed only between two consecutive fold and unfold features. In addition, if the user has defined a feature in one view, it is difficult for her to edit the feature and modify it using specifications in the other view.
There is therefore a need in the marketplace and a demand from users for a sheet metal part design system in which both the folded and the unfolded views of the part being designed are generally available at all times, or at least from time to time upon user""s request, without the user having to add superfluous features, such as the above-mentioned fold and unfold features.
Accordingly, the present invention provides a method and apparatus for computer-aided design and more particularly to the computer-aided design of sheet parts. The method includes defining a feature in a definition view based on a specification defined by a user and generating the feature in the definition view. The alternative view is then updated. This updating includes analyzing the defined feature to determine if it can be made available to an alternative view, and representing the defined feature in the alternative view. The definition view and the alternative view include a folded view and an unfolded view.
The analysis of the defined feature can include analyzing the defined feature in connection with previous features to determine if it can be made available in an alternative view. The updating step can also include the following steps. The feature can be stored in a list of features. A group of features connected through a relationship can be identified. The group can be searched for a connecting feature. The connecting feature can be stored in a feature list of transformations. The group can be searched for a connected feature linked to the connecting feature. Transformations for the connecting feature and the connected feature can be calculated. The connecting feature, connected feature, and their transformations can be stored in the feature list of transformations. The list of features can be searched for a supported feature. The feature list of transformations can be searched for a feature linked to the supported feature. The linked feature can cut the supported feature. The cut supported feature and its transformations can be stored in the feature list of transformations.
The transformations can be chosen from identity, cylindrical, and rigid transformations. A synchronous mode can be selected for automatically updating the alternative view. The alternative view can be updated at the request of a user. The definition view and the alternative view can be swapped at the request of a user. The folded view can include a three-dimensional view. The unfolded view can include a two-dimensional view. The definition view can be displayed in a computer window. The alternative view can be displayed in a different computer window. A list of features related to the definition view can be displayed in the window of the definition view. A list of features related to the alternative view can be displayed in the window of the alternative view. The design can include a sheet metal design. The alternative view can be concurrently updated according to changes made to the definition view.
In another embodiment, a computer system for computer aided design is presented. This system includes a computer. The computer includes a memory, a processor, a display device, and an input device. The system also includes executable software residing in the computer memory. The software is operative with the processor to define a feature in a definition view based on a specification defined by a user, generate the feature in the definition view, and update an alternative view. The update includes analyzing the defined feature to determine if it can be made available in the alternative view, and representing the defined feature in the alternative view. The definition view and the alternative view include a folded view and an unfolded view.
The input device can include a graphical input device for making changes to the definition view. The executable software can be further operative with the processor to display the definition view on the display device in a computer window and the alternative view in a separate computer window. The definition view and alternative view can be stored in a storage medium.
In another embodiment, a computer data signal embodied in a digital data stream for computer-aided design is presented. The computer data signal is generated by a method that includes transmitting over a computer communications network definitions of a feature in a definition view based on a specification defined by a user. Generated features in the definition view are also transmitted along with updates to an alternative view. The updates include the steps of analyzing the defined features to determine if it can be transformed to the alternative view, and transforming the defined features from the definition view to the alternative view. The definition view and the alternative view include a folded view and an unfolded view.
The computer data signal can include the step of receiving updates to the definition view. The generated data signal can adhere to the transmission control protocol/internet protocol.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Implementations can provide advantages such as a visualization system that allows concurrent design using simultaneous unfolded and folded representations of the sheet metal parts, creating an optimum and dedicated sheet metal part design environment. The propagation of a design modification from the folded representation to the unfolded representation and conversely can decrease the time and effort spent designing the sheet metal and increase the flexibility of the design. This is particularly true when features have to be reordered in the feature tree to take in account modifications of the original design.
The result is that a more efficient design environment for sheet metal parts can be achieved, which allows for a shortened design cycle that improves the quality of the part and understanding of the design by others by the suppression of unnecessary features.